Addition and Subtraction Problem Types and Strategies

Join Result Unknown	Join Change Unknown	Join Start Unknown
Separate Result Unknown (SRU)	Separate Change Unknown	Separate Start Unknown
Part Part Whole, Whole Unknown	Part Part Whole - Part Unknown
Compare Quantity Unknown	Compare Difference Unknown	Compare Referent Unknown

Direct Modeling:

Student has to directly see all of the pieces. They follow exactly what the problem says.



Counting:

The student counts everything, starting from one of the numbers in their head then counting up or down.



Facts:

The student uses fact strategies to problem solve.





Resources

Cognitively Guided Instruction Carpenter/Fennema

Addition and Subtractions Problem Types: Chapter 2, pg. 7-12

Addition and Subtraction Solution Strategies: Chapter 3, pg. 15-31

• Direct Modeling, pg. 15
• Counting, pg. 18
• Number Facts, pg. 24

Invented Strategies

Incremental

Combining Tens and Ones

Compensation